Got a 2012 that we got in May. It had 14500 miles on it then. We now have 19500. The wife uses it for work and the first 4000 miles we used 10 gal of gas and that is because we got it with a full tank and the Volt used it because the gas was getting old. We are in the Chicago area and now the ICE runs a lot more. It has developed a rattle in the right rear. Almost sounds like a shock is loose. Has anybody ran into this and any ideas on what to look for.